The PurpleCircBuffer implementation in Pidgin (formerly Gaim) before 2.5.6 does not properly maintain a certain buffer, which allows remote attackers to cause a denial of service (memory corruption and application crash) via vectors involving the (1) XMPP or (2) Sametime protocol.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.053
EPSS Ranking 89.5%